Fail safe marine engine cooling



June 6, 1967 J. M. WHALEN 3,323,502

FAIL SAFE MARINE ENGINE COOLING Filed May 19, 1965 F/G ff? INVENTOR. JOHN M. h/fi/AiLE/V Arm/015w United States Patent 3,323,502 FAIL SAFE MAE ENGINE COOLING John M. Whalen, Zion, lillL, assignor to Outboard Marine Corporation, Waukegan, llll., a corporation of Delaware Filed May 19, 1965, Ser. No. 457,029 3 Claims. ((31. 123--41.08)

ABSTRACT OF THE DISCLOSURE An engine cooling apparatus wherein the cooling jacket has a cold Water inlet and a recirculating water inlet, with a conduit system for supplying water to the inlets. If the cold water inlet conduit clogs, the system automatically switches to supply cold water to the cooling jacket through the recirculating water inlet.

The invention relates to marine propulsion devices and, more particularly, to cooling systems for marine propulsion devices.

An important object of the present invention is to provide a marine propulsion device having an auxiliary cooling system which is operative to supply coolant flow to an internal combustion engine upon failure of the primary cooling system. In the disclosed construction, the marine propulsion device includes an internal combustion engine having a cooling jacket, means including a ram jet water inlet for normally supplying coolant flow from the ram jet inlet to the cooling jacket, and other means for afltorcling coolant flow from the ram jet inlet to the cooling jacket in the event of a blockage in the means for normally supplying coolant flow to the cooling jacket.

Other objects and advantages will become apparent from the following description and the accompanying drawings in which:

FIGURE 1 is a partially sectioned and partially diagrammatic view of a marine propulsion device embodying various of the features of the present invention; and

FIGURE 2 is an enlarged fragmentary view of a part of the marine propulsion device shown in FIGURE 1 showing another form of the present invention.

Shown in the drawings is a marine propulsion device including an internal combustion engine 11 and a lower unit 12. The propeller 14 carried by the lower unit 12 is drivingly connected to the engine 11 by a conventional power transmission means (not shown). The lower unit 12 includes a ram jet inlet 16 disposed below a cavitation plate 18 and behind the propeller 14, When the propulsion device 10 is operating in a forward drive condition water is pumped from the inlet 16 by a conventional pump 20. When the marine propulsion device 10 is operating in the reverse drive condition, exhaust gases emitting from the exhaust outlet 22 collect around inlet 16 and make it undesirable to pump cooling water from the inlet 16. Accordingly, cooling water is then pumped from a side inlet 30 dis-posed above the cavitation plate 18 and on the side of the lower unit 12. Suitable valve means 32 is employed to normally block the side inlet 30 when the ram jet inlet 16 is supplying water to the pump.

In a conventional cooling system, such as the primary or recirculating cooling system shown in FIGURE 1, means for normally supplying coolant flow to the engine 11 (as shown by solid arrows in FIGURE 1) generally includes the pump disposed in an engine supply conduit 36 which connects both of the inlets 16 and to an inlet to the cooling jacket 38 surrounding the engine 11. The pump 20 delivers cooling water from either of the inlets 16 and 30 through the conduit 36 to the cooling jacket 38, wherein the water circulates around the cylinders of the engine 11. The coolant then flows from the jacket 38 into a thermostatic valve unit 40 by means of an engine discharge conduit 42 connecting the jacket 38 to the thermostatic valve unit 40. The thermostatic valve unit 40 includes a spring loaded thermostatic valve 44 designed to open at a predetermined temperature and a spring loaded check valve 46 designed to open at a predetermined pressure. The thermostatic valve 44 and the check valve 46 are normally retained .in the closed portions by the springs 47 and 48 respectively.

If the temperature of the coolant in the thermostatic valve unit 40 is above said predetermined temperature, the thermostatic valve 44 will open (as shown in broken lines in FIGURE 1) and allow the coolant to flow through the valve 44 and over-board by means of an over-board conduit 49. If the temperature of the coolant is below said predetermined temperature, the thermostatic valve 44 will be closed and the coolant under pressure of the pump 20 will unseat the check valve 46 (as shown in broken lines in FIGURE 1) and flow back to the pump 20 by means of a recirculating conduit 50 connecting the valve unit 40 to the inlet 16. The coolant flowing in the recirculating conduit 50 will mix with fresh. coolant and will be circulated through the cooling system.

The auxiliary cooling system of the invention includes other means for affording coolant flow from the inlet 16 to the cooling jacket 33 (as shown by the broken arrows in FIGURE 1) in the event of a blockage of said means for normally supplying coolant flow to the engine 11. Said other means generally comprises an auxiliary conduit, other than the engine supply conduit 36, connecting the ram jet inlet with the cooling jacket 38. A check valve in the auxiliary conduit precludes water flow therethrough during normal coolant flow and permits coolant flow to the water jacket 38 in the event of a blockage in the means normally supplying coolant to the water jacket 38.

In the preferred embodiment, the auxiliary conduit generally includes another water inlet or safety conduit 52 connecting the water jacket 38 to the valve unit 40 and the recirculating conduit 50. The valve unit 40 serves to connect the safety conduit 52 to the recirculating conduit 50 by means of a port 54 in the valve unit 41} on the recirculating conduit side of the check valve 46. In this manner, the recirculating conduit of the recirculating cooling system also serves as part of the auxiliary conduit of the present invention. For this reason, a recirculating cooling system is particularly well suited for use with this invention. In order to prevent coolant flow in the auxiliary system when the primary system is operating, spring loaded check valve 56 is disposed in the safety conduit 52. The check valve 56 is normally retained in the closed position by the spring 57.

In the alternative construction, shown in FIGURE 2, the safety conduit 52 including check valve 56 can be connected directly to therecirculating conduit 50 thus eliminating port 54 in the valve unit 40.

In operation, a blockage in the means normally supplying a coolant flow to the cooling jacket 38, as for example a failure of the water pump 20, will cause the ram jet inlet 16, by action of the propeller blades 14 and the forward motion of the propulsion device 10, to force cooling water through the recirculating conduit 50. The ram jet inlet affords water pressure which is sufficient to unseat the check valve 56 (as shown in broken lines in FIGURE 1) and allow the cooling water to flow through the safety conduit 52 and to the water jacket 38. The coolant will then flow from the water jacket 38 through the discharge conduit 42 and into the valve unit 40. If the temperature of the coolant is high enough to open the thermostatic valve 44, the coolant will flow out the over-board conduit 49. If the temperature of the coolant in the valve unit 40 is not high enough to open the thermostatic valve 44, the coolant will remain in the cooling jacket 38 until 3 the temperature thereof becomes high enough to open the thermostatic valve 44. Also, if the thermostatic valve 44 is closed, the check valve 46 will not open because the ram jet pressure in the safety conduit 52 is on the back side of valve 46 and tends to hold it closed.

Although the disclosed construction has particular advantages in a recirculating system, various of the features of the invention are also applicable to other types of cooling systems, such as the so called blocking, by-pass and restriction systems.

As an alternative construction, particularly in cooling systems other than recirculating cooling systems, coolant water can be supplied to the engine in the event of a failure of the water pump by means in the form of a conduit connected between the inlet side and the outlet or engine supply conduit side of the water pump, and a one-Way check valve in the conduit preventing flow through the conduit when the pump is operating and allowing flow through the conduit in response to pressurized flow from the ram jet inlet when the pump is not operating. In this manner, cooling water under pressure of the ram jet inlet will bypass the inoperative water pump and flow to the engine through the engine supply conduit.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. A marine propulsion device comprising an internal combustion engine having a cooling jacket, means including a ram jet inlet and an engine supply conduit extending from said ram inlet to said cooling jacket for normally supplying coolant flow from said inlet to said cooling jacket, and means including another conduit communicating with said jacket for affording coolant flow from said inlet to said cooling jacket in the event of a blockage of said conduit.

2. A marine propulsion device comprising an internal combustion engine having a cooling jacket, a ram jet water inlet, means connecting said water inlet and said cooling jacket for normally providing coolant fiow from said inlet to said cooling jacket, a conduit connecting said water inlet and said cooling jacket, and a check valve in said conduit precluding coolant flow thereth-rough during normal coolant flow conditions and permitting coolant flow to said cooling jacket from said ram jet inlet in the event of a blockage in said means connecting said water inlet and said cooling jacket.

3. A marine propulsion device comprising an internal combustion engine having a cooling jacket, a ram jet water inlet, an engine supply conduit connecting said Water inlet and said cooling jacket, a water pump in said engine supply conduit for normally providing coolant flow from said inlet to said cooling jacket, a conduit connecting said water inlet and said cooling jacket, and a check valve in said conduit precluding water flow therethrough during normal coolant fiow conditions and for permitting waterflow to said cooling jacket from said ram jet inlet in the event of failure of said water pump causing a blockage of said engine supply conduit.

4. A cooling system for a marine propulsion device including an internal combustion engine having a cooling jacket, said cooling system comprising a ram jet water inlet, means connecting said water inlet and said cooling jacket for normally providing coolant flow from said inlet to said cooling jacket, a conduit connecting said water inlet and said cooling jacket, and a check valve in said conduit precluding coolant flow therethrough during normal coolant flow conditions and for permitting coolant flow to said cooling jacket from said ram jet inlet in the event of a blockage in said means for normally supplying coolant flow to said coolant jacket.

5. A marine propulsion device comprising an internal combustion engine having a cooling jacket, a ram jet water inlet, an engine supply conduit connecting said inlet to said cooling jacket, a water pump disposed in said engine supply conduit for normally afiording a coolant flow to said water jacket, an over-board conduit connected with said engine discharge conduit, a thermostatic valve in said over-board conduit for allowing passage of cooling water of a predetermined temperature through said over-board conduit, a recirculating conduit connecting said engine discharge conduit with said inlet, a check valve in said recirculating conduit for allowing passage of coolant water through said recirculating conduit when said thermostatic valve is closed, and means for affording coolant flow from said inlet to said cooling jacket in the event of a blockage of said means for normally supplying coolant flow to said cooling jacket.

6. A marine propulsion device as set forth in claim 5 wherein said means for affording fiow to and from said inlet to said cooling jacket comprises a safety conduit connected between said cooling jacket and said recirculating conduit, and a check valve disposed in said safety conduit precluding coolant flow therethrough during normal coolant flow conditions and permitting coolant flow to said cooling jacket from said ram jet inlet and at least particularly through said recirculating conduit in the event of the failure of coolant supply to said engine through said engine supply conduit.

7. A marine propulsion device comprising an internal combustion engine having a cooling jacket with two inlets, means for normally supplying coolant flow to one of said cooling jacket inlets and means including another conduit communicating with the other of said cooling jacket inlets for affording coolant flow to said cooling jacket in the event of blockage of said means for normally supplying coolant flow to said first cooling jacket inlet.

8. A marine propulsion device comprising an internal combustion engine having a cooling jacket with two inlets, means including an engine supply conduit communicating with one of said inlets for normally supplying coolant flow to said cooling jacket, and means including another conduit communicating with the other of said inlets for affording coolant flow to said cooling jacket in the event of blockage of said engine supply conduit.

References Cited UNITED STATES PATENTS 1,099,684 6/1914 Barlow 12341.09 3,137,281 6/1964 Fulker .5 X 3,274,970 9/1966 Daniel 115.5

MARK NEWMAN, Primary Examiner.

RALPH D. BLAKESLEE, Examiner. 

1. A MARINE PROPULSION DEVICE COMPRISING AN INTERNAL COMBUSTION ENGINE HAVING A COOLING JACKET, MEANS INCLUDING A RAM JET INLET AND AN ENGINE SUPPLY CONDUIT EXTENDING FROM SAID RAM INLET TO SAID COOLING JACKET FOR NORMALLY SUPPLYING COOLANT FLOW FROM SAID INLET TO SAID COOLING JACKET, AND MEANS INCLUDING ANOTHER CONDUIT COMMUNICATING WITH SAID JACKET FOR AFFORDING COLLANT FLOW FROM SAID INLET TO SAID COOLING JACKET IN THE EVENT OF A BLOCKAGE OF SAID CONDUIT.
 8. A MARINE PROPULSION DEVICE COMPRISING AN INTERNAL COMBUSTION ENGINE HAVING A COOLING JACKET WITH TWO INLETS, MEANS INCLUDING AN ENGINE SUPPLY CONDUIT COMMUNICATING WITH ONE OF SAID INLETS FOR NORMALLY SUPPLYING COOLANT FLOW TO SAID COOLING JACKET, AND MEANS INCLUDING ANOTHER CONDUIT COMMUNICATING WITH THE OTHER OF SAID INLETS FOR AFFORDING COOLANT FLOW TO SAID COOLING JACKET IN THE EVENT OF BLOCKAGE OF SAID ENGINE SUPPLY CONDUIT. 